Our Q&A blogs with conservation experts explore shared priorities for sustainable tuna fisheries and marine ecosystem health, including how ISSF’s work contributes to these efforts. The views expressed by the experts we interview are their own.
In this blog on Shark Awareness Day (July 14), we talked with Sonja Fordham, the founder of Shark Advocates International — a non-profit (501c3) project of The Ocean Foundation — and a member of ISSF’s Environmental Stakeholder Committee.
ISSF: Why are sharks so important to healthy ocean ecosystems?
Sonja Fordham: Most sharks, particularly the species that swim near and are caught alongside tunas, intentionally or unintentionally, serve as top predators in oceans. Although research into their role in complex marine ecosystems is ongoing, these sharks are generally considered vital for preying on weak and wounded fish and thereby keeping those populations healthy and in balance.
ISSF: What are the biggest threats facing sharks today?
Sonja Fordham: The overwhelming cause of dramatic declines in shark populations is overfishing through both targeted and accidental catches.
Sharks and rays — part of the same taxonomic class (Chondrichthyes, or fish with cartilage skeletons), face similar pressures from commercial tuna fishing. While coastal rays — the sawfishes, guitarfishes, and wedgefishes — are the most endangered species in this group, pelagic sharks (and oceanic rays like mantas) are also in a precarious state.
For example, a 2021 analysis in Nature found a 71% decline in global pelagic shark and ray abundance since 1970, a period when catches tripled. Three-quarters of these species are now categorized as threatened on the IUCN Red List. Incidental or bycatch mortality in tuna and other pelagic fisheries is the main threat to Critically Endangered and globally protected oceanic whitetip sharks. Endangered shortfin mako sharks face additional risk from targeted fishing due to the relatively high market value of their meat and fins — and their lack of protection in most oceans.
ISSF: How do tuna fisheries management and shark bycatch mitigation efforts fit into that picture?
Sonja Fordham: Pelagic sharks have much lower reproductive capacity than tunas because of slow growth, late maturity, and few young. Sharks therefore warrant an even more precautionary approach in fisheries management.
While celebrations like Shark Week suggest that sharks are popular with the public, this appreciation has blossomed rather recently and is not necessarily being reflected in RFMO decision-making on shark protections. Sharks in fact have long been low-priority species within tuna management arenas, due to their relatively low commercial value and negative perceptions. As a result, there’s a paucity of long-term shark catch data that hampers scientific shark population assessments — and insufficient demand for conservation action as a result.
ISSF: Which advances in shark and ray conservation and management have been most encouraging over the past decade?
Sonja Fordham: While I have been involved in many successful efforts to ban the retention of particularly vulnerable or imperiled shark and ray species, I am particularly proud of the hard-fought progress in the Atlantic toward setting international fishing limits on commercially valuable shark species.
Most notably, the International Commission for Conservation of Atlantic Tunas (ICCAT) — one of the world’s four major tropical-tuna Regional Fishery Management Organizations (RFMOs) — has adopted science-based fishing limits on North and South Atlantic blue sharks for fleets in its region. ICCAT has also allocated overall blue shark quotas among fishing nations, which is vital for accountability on avoiding quota overages.
I’m also encouraged by ICCAT’s increasing, country-specific scrutiny of vessel compliance with shark and ray conservation measures. In both of these areas, ICCAT serves as a good model for the other tropical-tuna RFMOs, which have not set limits on fishing commercially exploited blue (or mako) sharks — and lack rigor and transparency in their compliance monitoring of bycatch measures overall.
ISSF: Which approaches show the greatest promise for reducing shark and ray bycatch and improving survival?
Sonja Fordham: For me, the most exciting bycatch reduction advance in recent years has been the development of a sorting grid fishers can use to safely remove incidentally caught manta and devil rays (mobulids) from purse seines and release them back into the ocean.
For leading this initiative, Dr. Melissa Cronin won the Grand Prize in ISSF’s 2020 Seafood Sustainability Contest. Through further testing, she has now demonstrated how the grid can be used to quickly release mobulids while keeping them flat and untwisted, which lessens their stress and increases their chances of survival. The grid’s simplicity and low cost improve its broad adoption potential in tuna fisheries.
On sharks, ISSF has long led research and policy work to mitigate bycatch, and support the safe release, of oceanic whitetip and silky sharks in purse-seine fisheries. ISSF also has been successful in efforts to end the use of traditional fish aggregating device (FAD) designs that entangle sharks and other species.
There also is increasing interest in shifting pelagic longline fishers away from using wire leaders and J-shaped hooks, which contribute to shark and other species bycatch, and switching to monofilament leaders and large circle hooks. Large circle hooks cause less internal damage to sharks than J-hooks but have been associated with increased shark catch in some studies. Monofilament leaders can reduce shark bycatch because the sharks are more able to bite their way free. Two RFMOs, the Western and Central Pacific Fisheries Commission (WCPFC) and the Indian Ocean Tuna Commission (IOTC), have taken steps to restrict the use of wire leaders; however, despite broad support for that restriction, governments with fleets that want to retain shark catches have resisted requiring fishers to use monofilament leaders.
ISSF: Can you describe some of Shark Advocates International’s current collaborative projects with other NGOs?
Sonja Fordham: I’m really grateful that SAI is able to collaborate with other NGOs through the ISSF Environmental Stakeholder Committee and the NGO Tuna Forum. These initiatives are made up of groups with varied expertise and priorities, yet we have very similar conservation goals when it comes to high-seas tuna fisheries. We find that a large array of organizations delivering the same message can greatly enhance individual groups’ influence, and of course we learn a lot from each other.
My international fisheries work is focused on the Atlantic and carried out in close coordination with Shark Trust and Ecology Action Centre as part of a coalition called the Shark League. Our website (sharkleague.org) has a wealth of information on our specific shark conservation priorities for ICCAT.
Q. In closing, what are the top actions tuna RFMOs could take today to better protect shark populations?
Sonja Fordham: First, RFMOs could act immediately to strengthen their bans on the wasteful practice of shark finning (slicing off a shark’s fins and discarding the carcass at sea) by requiring that all sharks be landed with their fins still attached without exceptions or alternatives. This is by far the most reliable way to enforce finning bans. It also would help to collect more species-specific catch data that is vital for assessing populations and monitoring compliance with other protections. Over nearly two decades, most of the world’s fishing nations at all the tuna RFMOs have supported such a change, but a small number continue to block adoption (without exceptions).
Another urgently needed improvement is increased monitoring of RFMO-managed pelagic longline fleets globally. Increased observer coverage (at least 20% but ideally reaching 100%) is essential for reliably recording bycatch of non-target species (including sharks), supporting robust population assessments for commercial species (including sharks), monitoring implementation of bycatch measures or catch limits, and evaluating a variety of bycatch mitigation measures.
And finally, until sustainable catch levels can be determined with reasonable certainty, RFMOs should also be setting precautionary limits for all pelagic shark and rays, including retention bans for particularly vulnerable species.
